Can styrene in Styrofoam cups damage your DNA?
Do not treat one Styrofoam cup like an emergency. But for hot drinks, glass or stoneware is the better daily choice because styrene can migrate from polystyrene cups and styrene metabolites have DNA-damage evidence in lab studies.
What the research says
Styrofoam is a common name for foamed polystyrene. Polystyrene can contain styrene, and styrene can move from some cups into hot drinks.
A 2009 Toxicology Mechanisms and Methods study tested hot tea, hot milk, and hot cocoa in polystyrene cups. The researchers measured styrene migration into all 3 drinks, with levels changing by cup type, temperature, and time.
What this means for DNA
The DNA part needs careful wording. The cup study measured migration. It did not test DNA damage in people drinking from cups.
A separate 2002 Toxicology Letters lab study found that styrene-7,8-oxide, a main styrene metabolite, caused DNA damage in human white blood cells at higher test concentrations. That supports taking styrene seriously, but it does not prove a single cup damages your DNA.
What to do at home
Use glass, stoneware, or stainless steel for hot drinks when you can. Be extra careful with hot, fatty, or long-sitting foods in polystyrene containers.
The bottom line: skip Styrofoam for daily hot drinks. A glass cup is a simple swap that removes this food-contact material from your routine.